Is carrageenan safe as a food additive? There has been a lot of controversy about this recently – made popular by bloggers who are eager to call out companies that might be using suspect ingredients. So, I decided to get to the bottom of it. I was particularly interested because a few brands that I really like still use it.
What is Carrageenan?
Carrageenan, an ingredient derived from various species of red seaweed, has been used for hundreds of years as a thickener in foods and was first made commercially in 1940 for chocolate milk and junket, a milk dessert similar to pudding. In the mid 1960’s, it was common for doctors to recommend carrageenan to reduce pain associated with peptic ulcers. The concentration needed to provide ulcer relief created a gel that was extremely viscous and unpleasant to consume. Subsequently, degraded carrageenan, also known as poligeenan, was created. Degraded carrageenan is produced by hydrolyzing native (food grade) carrageenan which cuts bonds and makes the molecules smaller thus removing their thickening properties. Soon, degraded carrageenan was found to be harmful and its use for ulcer treatment was discontinued. Since the function of carrageenan used in foods is to thicken, degraded carrageenan, having little or no thickening properties, never had a use in foods. Even though degraded carrageenan and food-grade carrageenan are different, the harmful effects of carrageenan in its degraded form have been mistakenly associated with food-grade carrageenan.
Why is there concern about Carrageenan?
The driving force behind concerns regarding carrageenan’s safety is attributed to an article written by Dr. Joanne Tobacman. Most of the studies cited in her article report on degraded carrageenan (poligeenan). She argues that even food-grade carrageenan is not safe from having significant levels of degraded carrageenan because the acids in our stomach as well as certain bacteria might break it down into degraded carrageenan. This is not a claim supported by human or animal studies. Tobacman references studies that simulate gastric acid effects on carrageenan and the resulting presence of degraded carrageenan. However, a study in 1969 by Marcus and Watt explains that “poligeenan with an average molecular weight of about 20,000 daltons has none of the food functions of carrageenan whose average molecular weight is never lower than 100,000 daltons and is usually much higher.” Therefore, comparing “digested” carrageenan to poligeenan is a false equivalency.
More recently, scientific assessments of carrageenan have included short term and long term generational studies involving different dosages of degraded and non-degraded forms and various animal studies … all of the studies supported the safety of [food grade] carrageenan for use in foods. Regulatory authorities saw no reason to question the safety of [food grade] carrageenan as long as the average molecular weight was 100,000 daltons or higher. The regulations of carrageenan molecular sizes were modified to insure that the food-grade carrageenan in foods was never lower than that limit, and testing methods were introduced to enforce these limits.
Tobacman also references studies that show that native carrageenan can promote colonic tumors in rats; however, the carrageenan in these studies made up anywhere between 2.5% and 15% of the rats’ total diets. In contrast, foods that contain carrageenan have the ingredient at tenths (.1%) or hundredths (.01%) of a percent within the food and these foods make up only a small fraction of our overall diet.
How do we know that carrageenan is a safe food additive?
Dr. Tobacman’s research was reviewed by the Joint FAO*/WHO** Expert Committee on Food Additives (JECFA), an independent international panel of expert toxicologists who review data and develop recommendations pertaining to food ingredients. Their review of the study, and of carrageenan, included an evaluation of degradation of carrageenan and “public speculation of the harmful gastrointestinal effects” of carrageenan. As a result of the evaluation, the JECFA committee determined that the studies of carrageenan on laboratory animals were conducted with high levels of degraded carrageenan (poligeenan) and that food-grade carrageenan was a safe food additive with no limits on its use in food. Those studies used a different form of carrageenan and were tested only at high use levels. The JECFA determined that carrageenan was a safe food additive with no limits on its use in food and “assigned it an acceptable daily intake (ADI) of “not specified” the most favorable category. An ADI of 0-75mg/kg body weight is established in the EU” and is allowed to be used as needed.
Other studies
Since Tobacman’s aforementioned article, she also wrote a paper noting that bench-top invitro experiments showed interactions between carrageenan and various organ cells. These experiments are considered invalid because ingested carrageenan does not pass the blood-gut barrier to interact with organ cells. She also wrote a paper noting the “time-trend” that carrageenan consumption and the incidence of breast cancer both increased in the 20th century. The European Commission Scientific Committee for Food stated that such correlations might be found for any food or chemical which has increased in prevalence during the 20th century. Saying that carrageenan must induce breast cancer because breast cancer incidence and carrageenan consumption both increase during the 20th century is like saying that listening to Jimi Hendrix and the prevalence of rock n roll music must also induce breast cancer.
Tobacman is doing her best to defend her case against food-grade carrageenan regardless of the science behind the arguments and is not recognizing the true difference between degraded carrageenan and food-grade carrageenan. The scientific literature supports the safety of carrageenan and even shows carrageenan to inhibit cancer cell growth due to its enhancement of the immune system.
My Take
For now I (and I am always open to changing my opinion), the scientific research I’ve found, points to the fact that we don’t need to freak out about carrageenan as a food additive. There is some concern that it might irritate the gut lining of those who have inflammatory gut concerns such as Crohn’s disease or severe IBS – in both of those cases, I would probably avoid it, along with as many other food additives as you can.
*FAO = Food and Agriculture Organization of the United Nations
**WHO = World Health Organization
Sources:
Carrageenan: a review from Veterinarni Medicina, 58, 2013 (4): 187–205 http://vri.cz/docs/vetmed/58-4-187.pdf
Stanley N (1987) Production, properties and uses of carrageenan. In:McHugh DF (ed.) Production and utilization of products from commercial seaweeds, vol 288. FAO, Rome
Champman VJ (1950) Seaweeds and their uses. 1st ed. Camelot Press, London
Tobacman JK (2001) Review of harmful gastrointestinaleffects of carrageenan in animal experiments. Environ Health Perspect 109:983-994.
Marcus AJ, Watt J (1969) Ulcerative colitis guinea-pig caused by seaweed extract. J Pharmceut Pharmacol 21:187.
Watson DB (2008) Public health and carrageenan regulation: a review and analysis. J Appl Phycol 20:505-513.
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Borthakur A, Bhattacharyya S, Dudeja PK, Tobacman JK (2007) Carrageenan induces interleukin-8 production through distinct Bc110 pathway in normal human colonic epithelial cells. Am J Physiol Gastrointest Liver Physiol 292:G829-G838.
Tobacman JK, Wallace RB, Zimmerman MB (2001) Consumption of carrageenan and other water-soluble polymers used as food additives and incidence of mammary carcinoma. Med Hypotheses 56:589-598.
Scientific Committee on Food (2003) Opinion of the Scientific Committee on Food on carrageenan. Brussels: European Commission; 5 March. (SCF/CS/ADD/EMU/199 Final)
Yuan H, Song J, Li X, Li N, Dai J (2006) Immunomodulation and antitumor activity of [kappa]-carrageenan oligosaccharides. Cancer Lett 243:228-234.
